Federal authorities have charged a man with distributing heroin laced with a deadly synthetic opioid that last turned up during a rash of overdose deaths in the Twin Cities this year.

A criminal complaint filed in federal court Friday noted the deaths of 11 people who ingested carfentanil between January and April, though it did not specify whether John Henry Edmonds, 34, was among those suspected of supplying the fatal doses.

The U.S. attorney's office filed charges of distributing heroin and carfentanil against Edmonds, who was arrested Sept. 20 by Bloomington police and remains jailed awaiting his first appearance in federal court.

An attorney has not yet been listed for Edmonds and the U.S. attorney's office declined to comment.

It is the first case charged by federal prosecutors in the state involving carfentanil, an opioid 10,000 times more potent than morphine typically used to tranquilize elephants and other large animals.

Drug Enforcement Administration agents probing carfentanil's deadly emergence in the Twin Cities used a confidential informant to conduct a series of controlled purchases from Edmonds in Minneapolis this summer.

According to charges, a DEA forensic laboratory confirmed that the first sample allegedly supplied by Edmonds contained heroin and carfentanil. A second sample also contained "furanyl fentanyl," and Minnesota Bureau of Criminal Apprehension scientists confirmed that the third sample contained heroin, carfentanil and furanyl fentanyl "or an isomer thereof."

Edmonds allegedly sold the carfentanil-laced heroin to the informant between July 21 and Aug. 22, months after the last publicly disclosed overdose death in the Twin Cities metro.

The federal complaint does not link Edmonds to this year's deaths, but a DEA agent wrote that it "should further be noted" that law enforcement suspected the spate of overdose deaths were linked to substances containing carfentanil and that the deaths happened after the substance was ingested "in ways consistent with methods used to ingest heroin."

Officials have said just two salt-sized grains of carfen­tanil can instantly kill users, and the DEA issued guidance earlier this year to law enforcement and other first responders on avoiding accidental contact with the substance.

New on the streets

Until this year, law enforcement rarely encountered carfentanil on the streets. Of the 11 documented carfentanil deaths in Minnesota this year, all but one occurred in the Twin Cities metro area.

Authorities said the victims — who ranged from 23 to 43 years old — most likely didn't know that carfen­tanil had been laced into the heroin that they purchased, and that it was also unclear whether even their dealers were aware that the substance had been mixed into the product.

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